The present invention relates to a cutter apparatus, and more particularly to a cutter apparatus for a compact printer which is used for an electronic device such as a POS (point of sale) terminal or the like.
The compact printer which is used for the electronic device such as the POS terminal or the like and executes printing on a roll sheet is provided with a cutter apparatus for cutting the printed roll sheet at a proper position (length).
This type of cutter apparatus is structured such as to cut the roll sheet positioned within a paper carrying path by arranging a fixed blade and a movable blade while arranging the paper carrying path therebetween, and moving the movable blade to the fixed blade side. Generally, the fixed blade and the movable blade are respectively attached to a base frame and an upper frame of the printer which are assembled so as to be openable and closable with each other, while taking an easiness for setting the printer to the roll sheet or the like into consideration.
In this case, in this type of cuter apparatus, there is a case that it is impossible to completely cut the roll sheet at a time of cutting the roll sheet, and the roll sheet is tucked down. This is called as a paper jam. In order to solve the paper jam, it is necessary to detach the movable blade from the fixed blade so as to return to a home position.
Since the conventional cutter apparatus quickly return the movable blade to the home position in the case that the paper jam is generated, the conventional cutter apparatus is structured such that the movable blade is returned to the home position by moving the upper frame from a closed state to an open state (for example, refer to Japanese Unexamined Patent Publication No. 2001-121480).
In other words, the conventional cutter apparatus is structured such that the movable blade is provided in the upper frame, a drive source for driving the movable blade is provided in the base frame, a driving force transmission mechanism for transmitting the driving force from the driving source to the movable blade is provided in at least one of the base frame and the upper frame, and a return spring for energizing the movable blade toward the home position is provided. In this structure, when moving the upper frame from the closed state to the open state, a driving force transmission path connecting the movable blade and the driving source is disconnected. Further, the movable blade disconnected from the driving force supplied from the driving source is returned to the home position on the basis of the energizing force of the return spring.
The conventional cutter apparatus is structured such that the driving force transmission path between the driving source and the movable blade is disconnected at a time of moving the upper frame from the closed state to the open state. Accordingly, in the conventional cutter apparatus, there is a problem that the movable blade can be returned to the home position only by opening the upper frame, in the case that the paper jam is generated.
In detail, the movable blade is exposed to the pressure from the fixed blade, in the state of the paper jam. The pressure is transmitted to the upper frame from the movable blade, and transmitted from the upper frame to a latch mechanism latching the upper frame to a closed position, thereby preventing a latch canceling motion of the upper frame. Accordingly, in the state of the paper jam, there is a case that even if it is intended to move the upper frame from the closed state to the open position by operating an opening and closing lever or the like, the upper frame holds the closed state. In this case, the movable blade and the driving source hold being coupled by the driving force transmission path, and it is impossible to return the movable blade to the home position.
Further, since the conventional cutter apparatus is structured as mentioned above, it is necessary to open the upper frame to some degree in order to disconnect the driving force transmission path between the driving source and the movable blade. Accordingly, in the case that the paper jam is generated, it is necessary to open the upper frame until the driving force transmission path is disconnected while keeping a state in which the movable blade protrudes. In this point of view, the conventional cutter apparatus has a problem that a comparatively large space allowing the movement of the protruding movable blade is required above the fixed blade.